The buff ideas you mentioned would force people to play one specific way and would take away a great deal of options.
About the "random" stuff, good strategy games put a limit on randomness. Anything random that is currently in the game can actually be controlled to a degree (ex: putting archers closer to enemies will make them miss less often). Adding more randomness would be bad, especially with movement due to how important it is in this game.
As for the weakness-related stuff, there's already quite a bit of counter-play available. Not every counter need to be based on an element or attack type.